Physics Work Power and Energy Mcqs
The example of negative work is:
(a) Work done under a conservative force
(b) Work done perpendicular to a conservation force
(c) Work done against friction,
(d) Work done against gravity
2. The work done by centripetal force is:
(a) Equal to that of centrifugal force. (b) Greater than that of centrifugal force
(c) Variable in different cases. (d) Zero
3. Work is defined as
(a) Scalar product of force and displacement.
(b) Vector product of force and displacement
(c) Scalar product of force and velocity
(d) Vector product of force and velocity
4. The work done on a body under going a certain displacement is given by:
(a) The area under a force vs. time curve
(b) The area under a force vs. distance curve
(c) The area under a velocity vs time curve
(d) The area under an acceleration vs time curve
5. Work is always done in a body when
(a) A force action on it
(b) It covers some displacement.
(c) Force moves it in its direction or in opposite directions
(d) The resultant force on its is zero.
6. The work given to the machine is called:
(a) Input (b) Output
(c) Velocity ratio (d) Mechanical advantage
7. All of them are true accept:
(a) Work is defined as the product of force and distance.
(b) Joule is the unit of work.
(c) Force moves in its direction or in opposite directions.
(d) The resultant force on it is zero.
8. Work done will be zero when force and displacement are
(a) In the same direction (b) In opposite direction
(c) Perpendicular to each other (d) Not zero
9. The energy due the motion of a mass is known as.
(a) A. Potential energy (b) Motion energy
(c) Mobile energy (d) Kinetic energy
10. The amount of work required to stop a moving object is equal to the:
(a) Velocity of the object (b) Kinetic energy of the object
(c) Mass of the object times its acceleration
(d) Mass of the object times its velocity
11. Power is the dot product of.
(a) Mass & velocity (b) Force & velocity
(c) Force & Energy (d) Force & mass
12. The sum of kinetic and potential energies of a falling body
(a) Is constant at all points. (b) Is maximum in the beging
(c) Is minimum in the beginning (d) Is maximum in the middle of the path
13. Potential energy is increased when the work is done,
(a) Along the field (b) Against the field
(c) By the field (d) All of the above in different cases
14. If the velocity of the moving particle is double the factor by, which the K. E is increased is.
(a) 4 (b) ½ (c) 2 (d) 6
15. The heat energy is transferred to a body, it is converted into:
(a) Internal energy of the body (b) work done by the body
(c) Mass of the molecules (d) Potential energy of the body
16. The tidal energy is due to:
(a) The rotation of earth about sun (b) The rotation of earth relative moon
(c) The radio active decay inside earth (d) Attraction of sun and moon
17. Energy is:
(a) Work divided by time (b) The ability to do work
(c) Measurable in Horse Power (d) Force divided by distance
18. The work done in moving a object along a vector=3i + 2j – 5k. If the applied force is F = 2i–j – k:
(a) 10j (b) 6i – 2j – 5k (c) 0j (d) 9j
19. The power required to lift a 40 kg. weight up to the height of 5 m in 10 sec will be
(a) 80 watts (b) 200 watts (c) 28 watts (d) 14000 watts
20. The K. E of a 1000 kg car moving at a speed of 80 km/hr will be.
(a) 2.47×108 J (b) 2.47×105 J (c) 24.7×107 J (d) 24.7×103 J
Chapter # 7
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b A b a a d b D b B